Extraction and Chemical Characterization of Humic Acid from Nitric Acid Treated Lignite and Bituminous Coal Samples

Currently, conversion of coal into alternative fuel and non-fuel valuable products is in demand growing interest. In the present study, humic acid was extracted from two different ranks coal, i.e., low rank high (lignite bituminous), through chemical pretreatment by nitric acid. Samples lignite bituminous were subjected to oxidation followed extraction using KOH NaOH gravimetric techniques. The both types led enhanced yields 21.15% 57.8% for low-rank 11.6% 49.6% coal. derived native treated analyzed elemental analysis, E4/E6 ratio absorbance at 465 nm 665 UV-Visible spectrophotometry Fourier transformed infrared spectroscopy FTIR. characteristics with have shown increased molecular weight improved aromaticity more oxygen nitrogen lower C, H, sulphur content. acid-treated high. FTIR spectroscopic data indicates an intensive peak carboxyl group 2981.84 cm?1, while cooperation N-H 2923.04 cm?1. SEM performed detect morphological changes that happen after producing HNO3 treatment produced had clear some deformations on surface. SEM-EDS detected major elements, such as nitrogen, absent raw Hence, showed a significant number materials efficiency compared This obtained can be made bioactive agriculture purposes, soil enrichment improvement growth conditions plants development green energy solutions.